Position and altitude finder



July 4, 1933. E. H. L Ewls 1,916,765

POSITION AND ALTITUDE FINDER Filed March 21, 1931 2 Sheets-Sheet 1 'NVV IIllllllllllllllllllllllllll llll'l 5957 5555514947454341:59375531332927252321:emanan a 7 5 31 1 2468 '85 |7- lllllllllllllllllllllllllllll Il llllvlllllllllllllllllllllll ll 5856845250484644424038363432302826E#2220I8|614l2l0864 E 1 3'57. -22- I I I l F/G. 7 4/ e @VEA/Tof?.

/V ATTORNEY July 4, 1933.

Filed March 2l, 1931 2 Sheets-SheetI 2 F-IG- l2.

/N VENTO/Q.

dfw.

Patented July 4, 1933 UNITED-STATES ERNEST HENRY Liaw'is, or VERDUN, QUEBEC, CANADA,

PosiTIoN AND ALTITUDE FINDER Application filed-March 21, 1931. Serial No.;'5v24,310.

The invention relates to a position and altitude finder, as described in the present speci-` ication and illustrated in the accompanying tances from'a given point on a movingv or movable calculator, as vpointed out in the "i claims for novelty vfollowing a description in detail of the parts and their relationships required to carry out the objects of this invention. The objects of the invention are to facilitate the finding of a'position of a ship at sea'in relationto any fixed object, such as a lighthouse, rocks, Shoals, islands, point-s and peninsulas or other marks that may prove dangerous or that may enable the master of ".30 the ship to guide his vesselto a predeterminedl destination and further to calculate distances of points out of the course of the ship and in the course of the ship for many purposes Y incidental to the use on the sea; to simplifyv the computation of distances onland, either parties; to insure a reasonable accuracy iii' the calculations both on land and at sea without the requirement of a deep knowledge of mathematics by the operating person, and in l this connection to furnish to the public a cal-f culating device Vthat will be of immense serv ice to such organizations as boy scouts and girl guides and also to students at schools and universities with whom an elementary knowll5 edge will be quite sufficientA to operate the position finder; and generally to provide a simple'and eiiicient instrument which will prove economical in so f ar as production and repair areconcerned and yet be of durable 5U and stable construction.

In the drawings, Figure l 'is a perspec-4 tive view of the position finder showing the longitudinal and transverse scales. t

FigureQ is an enlarged fragmentary view showing the longitudinal scale.

Figure 3 is a fragmentary view showing a transverse scale. Figure 4l is a fragmentary view showing a transverse scaleA for offside finding.v y

Figure 5 is an elevational view ofthevertical scale. y; i n Figure 6 is a perspective .detail of a, fixed sight. fl f" Figure 7 is fa perspectivedetail of the liXed sight for altitude finding. Y 6-5 Figure 8 is a perspective view ofthe trans-v verse movable'sight. n

Figure 9 is a perspective detail ofthe movable sight for altitude finding.v i

. Figure lO'is a diagrammatic view showing 70 a triangle on which the calculations' are" Y based, for range course or altitude findings.

Figure l1 isa diagrammatic view'showin'g a triangle r,on which .the'calculations are based,` particularly for offside, range or course find-V ings.-

Figure 12 is a diagrammatic view fory the offside object measurements 'showin g the` sec- 'ond sight line' and the original sight line 80 dotted. f

Like numerals of reference indicate corresponding parts in the various figures. s

Referring to the drawings, the board of the instrument is indicated'by the 'numeral 15, though it must be understood that this is not necessarily a board as it may be a block v or aA strip or it may take any form.y lwhich will lend itself to establishingthereon a lon-f gitudinal scale,` indicated by the lettersls. (Fig. 2)., 90 The longitudinal scale is so named-for the reason that this scale islalways'alon'g the line of direction, ywhich may otherwisebe" termed the course in seasworkand rthe range in land Work, but these terms may be applied'either`way,-still inl order to avoid: any confusion in the understanding of .this invention the two words will be usedfor what is otherwise the line of direction. This board is lshown 'with three slideways 10 Y 5 center and the other side edge of the board.

This board at what may be called the outer end has a bead 2O forming fa stop and the board itself may be mounted on the tripod 21 or on any suitable support, though a lo tripod is quite convenient, especiallyfl'or field work, and it is usual to mount a board of the lrind so that it may be turned and held by set screw to al temporary liXed position.

The scale ZS is made on one side of the slideway 17 and the graduations are numbered frei-none to one hundred and it is preferable to establish a definite length for the scale which in practice Vhas beenmade twelve and one half ,inches and it is Aon this longitudinal 29 scale that thesimple calculations are made by a percentage meth-od.

i This length of 'twelve and one half inches has vbeenmentioned for convenience in explanation, -as the longitudinal scale `may be any length desi-red. Y

On either side of the slideway 17 the scale is sh'ownin fractions ofthe twelve and one half in the length, as for instance, onee'leven'th, onedswel-fth, aonefsixth., one-fifth,

39 one-third,onehalf. Y

The percentagefside:ofthe scale is indicated by the letter a and the fnactien side of the scale is inc'licajtedEby-the Aletter' -while :Zero is indicated by the :letter fcc-and the other end `of the scafle., rthat is tofsay, 'the innerend, by the letter-d.

The transverse har y22 :is formed with the slideway 231eX-tending throughout its fwh'ole length 'and carries the :runners '24 sliding in thesli'deways 17, 18and 19, the head2() forming a stop for this transverse bar at the outer .end of the boar-d, `wh'ile the bar litself slides inwardly towards the person using the Ainstrument, being moved preferably l'by '-hand.

" The transverse front scalesl are indicated ,by the letters e landy" and the transverse top lScales are indicated by the letters g and 7L.

v`The transverse front scales e and'flrun in 50,.,consecutive numbers 'to the eXtreme 'ends of thet'ransverse bar 'and are marlred graduations levenly spaced, each scale starting at lgelo-indicated lby the letter on the transverse 55. The'top scales g and 7L (F ig. ll) are .somewhat different, as the'y areused in'conjunction with` the changing position of 4a sight line representing 'the hypothenuse of a triangle, in which the longitudinal scale ZS and Go front scale e or f form the sides of a right angle triangle,so v.the .graduations of the scales e and .f correspond to the .graduations of the scale ls, though ,gradnations of vthe front scales may extend .to'a'greater extent es' than the graduations .of the'alongitudinal scale, and Ynaturally they enable the calculator to compute the transverse distance. Y

To compute the distance represented bythe hypothenuse of the triangle, the percentage method is used and in this the graduations in the scales g and widen out in relation to one another, as they approach Zero from either end of the transverse bar and the percentage pointed out bythis line on a scaleV gV or L- is computed on the course line total dis-v tance and added thereto. Y

The fixed sight 25 is a block or shape from which the needle 26 projects upwardly and under which the strip 27 is attached, this strip being inserted'in the slideway 17 at the end of the scale Z3.

The movable sights 28 and 22 of suitable shape' are also-made with a 'needle and runner, slidingin the sl-i-deway123 of the trai'xsverse bar, the .sight 28 han. :the needie 30 inojecting upwardly therefrom :forinfy ing the sight and the sight :29 having .the needlel projecting upwardly therefrom. A.

The vertical scale is indicated ,by the letter n, the percentage side being indicated by the letters p?) and the fraction side by the let-:- ters fr). 1f f l.,

Ylhis vertical scale is made of a post 32 standing on a base V33 or otherwise'mou'ritedV and under which the runner 34 4is secured and sliding in the slideway 17 :in "pl-ace :of the 'y transverse barj22 or there-with as it may :befV

carried thereby.

The sight 35 is'formedfof a c'laInpings-leeve 36 engagingl the post, and airing?? extending outwardly therefrom and formingftlie Lactual sight.

sight 35 is moved upwardly for downwardly and aligns the fixed object beyond.

r-lhe fixed sight 39 is formedof the {bloc-k el() or other shape having the strip 41 :thereunder for insertion in: the -slideway 17 at the end of the longitudinalscale-Zaand:a straight edge'42 projectingupwardly for aligning with the sight 38 and Valso with the sight 35./ The operation of the instrument is-best illustrated hy the Yassnn'rption 'of an example. lf be assu-med th at v.the vessel lfis proceeding at ten knots Y and that a lighthouse is .observed at about three po-ints to starboard and it is yrotan-red to take observations on this liighthouse, the procedure wou-ldf-beas follows:

A similar .sight 38 is mounted Lon the post* 32 for determining the horizontal7 while the take a second bearing on the samel lighthouse by -moving `the horizontal sliding .bar aft until the sliding sight is again in line with the back sight land the lighthouse. Care must be takenV not to move the sliding sight on the horizontal bar during this observation; Note is nowtakenof `the indication given by the graduated scale along tlm centre line of the zontal sliding bar isn/nv standing. This percentage is the percentage which the distance of travel ofthe ship between the twov observa-A tions bears to the distance between the position of the ship when the first observation was taken and the position of the ship when the lighthouse will be directly abeam.

In the example, with a speed of ten knots and af time interval of six minutes, the distance travelled is one knot. If the graduation indicated by the pointer on the face ofV the horizontal sliding bar after the second'observation has been taken is nine percent (9%) then the one knot is nine percent (9%) of the distance from the ships first position to the abeam position, or in other words, the ship must travel slightly over eleven (11) knots Y from the position of the first observation in order to have the lighthouse directly abeam on the starboard side.

Note -is also taken of the graduation indicated on the scale graduated on the aft, face of the horizontal sliding bar by the pointer attached to the sliding sight. Thisfigure in-v dicates the ratio between the normal distance from the lighthouse to the straight line course of the vessel and the distance to be travelled by the vessel from the point of the first observation to the abeam point. vIn other words, if the pointer indicates the lighthouse is 40% of eleven knots, that is to say about four and Va half (4l/2) knots, to starboard of the straight course of the ship.

Thirdly, if it be desired to find the distance from the ships position at the first'observation directly to the lighthouse, the graduated scale on the top face of the horizontal sliding bar may be used. The figure on the scale indicated by the pointer on the sliding sight shows the percentage `by which this dii l rect distance exceeds the distance which the ship must travel from its first observation position to its abeam position. For instance in the example taken, the indication will be about ten percent (10%) meaning that the direct distance from the vessel to the lighthouse was almost 121/4c (twelve and one quarter) knots. f

In land use, the operation is just the same, the only difference being that in place of the moving ship, the instrument itself is advanced a length of ground previously chained, or measured out. What this length may be is entirely at the operators discretion G but the distance to the zero mark or to the base plate where the ytfteryface .ofI the lhori-`l right angle lis determined in exactly, the same y way, for the distance that the vinstrument is moved forwardly is taken as a basis for the percentage and from that percentage iscalculated the distance of the actual range line and also the distance of theri'ght angular projection vline to the object. All this may be done from either side as can readily be seen,- the object of course'isfixed.

kThe diagrammatic views help to explain the finding of the distance of an offside obj ect or infotherwords, the length of the hypothenuse of the triangle. n u f To do this the range or course line is made a'sightline andan object quite beyond the sight object is taken asv direction, and so sighted, then the `offsideobject islsightedalong l the hypothenuse ofa right angle triangle and a reading is taken ,on a top scale, say on the scale g or the scale L and this percentage is added to the length ofthe course orrange line,

the vrange of which has already been deteri mined on the same methods as have been carefully explained herein, that is' to say, if it is at sea the speed of the ship is used, and if it is on land the instrument is moved and the length of the line to zero calculated.

It will thus be seen that distances can be found with great ease and by very simple methods, such as Acan be understood by the lay mind, therefore, students and others may readily practice in'fields and on the water. Also'in more serious pursuits the instrument can be used with great advantage by the masters of ships and by locationengineers.

In determining distances in so far as altitude is concerned the same principle is used throughout. The right angle triangle is found by using the straight edge sight and the lower sight on the altitude post, the upper' sight being brought into alignment with the top of the elevation .and the calculation made in precisely the same way as has been fully describedl herein. n

It is of course obvious from the aforesaid description of the operation of the instrument that sights may be taken and distances measured above and below the level of the instrument itself, that is to say, if the instrument is supported on a level which is intermediate in so far as altitude is concerned of the levels of the objects, then therewill be two right angled triangles, thus the horizontal line will intersect a common base forming thereby a downwardly inclined hypothenuse and an upwardly inclined hypothenuse, the common lao longitudinal scale and' a scale at right angles thereto movable along said longitudinal scale on said base, a pair of sights adjustable on and' along saidright angular scale and a fixed sight atitlie inner end elisa-id longitudinal sl'ideway andv travelling from zero to the endv of the scale and return and having scales p extendingin opposite directions from azero mark coincident with said longitudinal scale, a fixed sight at the end of the longitudinal scale7 a pairo'f movable sights respectively on said scales of said transverse bar for supporting said board.

a board and meansv 31'. A position finder Vcomprisingav board having i aflongitudinal Scale in' respect to course orrange and a slideway parallel with sai ;l"scale,av pest extending upwardly from a basey having-a runner sliding'in said Way and carrying a 'vertical scale in consecutively numbered' graduations from Zero upwardly, a fixed 'sight having' a `straight Aedge and inserted in' said slid-away` at the end of said' longitudinal scale, a pair-of movable sights 'formed of sleeves and arms and adapted with said! straight edge to determine a horizontal sight Vline and the hypothenuseV of a calcul'ating triangle and means` for supporting y said board. f e i .K

f Signed at. Montreal, -Canada, this 21st day of February-1931'- f 1 :ERNEST HENRY' LEWIS; 

